This K08 award will enable the candidate, Kori L. Sauser, MD, MSc, to become an independent physician scientist focused on acute stroke systems of care specifically dedicated to improving the efficiency of evidence translation in order to improve patient outcomes. Acute ischemic stroke is common, yet there is broad variation in the care of stroke patients between hospitals. Many eligible patients do not receive disability-?reducing treatment; this results in greater neurologic damage and long-?term disability for patients, and large societal costs. Dr. Sauser's proposed study aims to better understand the organization of U.S. hospitals in the delivery of acute stroke care by creating a map of the U.S. stroke hospital transfer network, and then using this map to determine how performance and high-?quality care are disseminated between connected hospitals. To achieve these goals, this proposal includes an integrated curriculum consisting of intensive mentorship and didactic coursework in network analysis methodology, advanced statistical modeling, and organizational culture and implementation research. Her development and training activities also include building a research network, engaging with stakeholders in regional stroke networks, and participating in national scientific meetings. The rich academic environment at Massachusetts General Hospital and Harvard University is ideal for Dr. Sauser's training and has enabled her to assemble a mentorship team of national leaders with expertise in stroke health services research, epidemiology, network analysis methodology, healthcare quality measurement, and advanced statistical modeling. Dr. Sauser will utilize a linked dataset containing Medicare claims linked with the Get with the Guidelines-?Stroke clinical registry to create a map of the U.S. acute ischemic stroke transfer network. With this map she will: 1) describe factors related to choice of hospital transfer destination for transferred acute ischemic stroke patients (such as perceived hospital quality); 2) examine whether hospitals that are connected by frequent transfer of patients have more similar performance and quality of acute stroke care delivery; and 3) longitudinally examine these network relationships to understand the diffusion of performance and quality between hospitals in the network. Completion of this proposed project will produce a map of the U.S. stroke network and an understanding of how best practices for stroke flow through the network. This will help explain variation in quality at the hospital level, and inform next steps for improving stroke care delivery. Completing the proposed project and didactic training plan will also facilitate Dr. Sauser's transition to an independent health services investigator focused on improving the delivery of stroke care in the U.S.